In recent years, there has been rapid improvement in graphics display techniques aimed at providing a perception of three dimensions. Three dimensional images displayed on a two-dimensional screen using conventional display technology contain limited three dimensional cues such as obscuration, depth effect, and illumination effects. For enhanced three dimensional displays, special architectures depart from conventional two dimensional displays.
Two enhancements for three dimensional displays are stereopsis and parallax. Stereopsis may be achieved with various hardware such as shutters and headgear. It may also be achieved without special equipment, and the resulting displays are then referred to as “autostereoscopic displays”. When parallax is provided in the vertical as well as the horizontal dimensional, the display is referred to as a “full parallax” autostereoscopic display. Full parallax autostereoscopic displays include autostereoscopic displays such as full-parallax holographic stereograms, full-parallax lenticular or “fly's eye” displays, and full-parallax raster-barrier or parallax-barrier displays.
Methods for producing full parallax spatial displays require unconventional computer graphic rendering methods, such as the double frustum rendering method. This method uses two opposing camera frusta, one at either side of the image plane. An implementation of the double frustum method was developed by Michael Halle and Adam Kropp, and is described in the technical paper, “Fast Computer Graphics Rendering for Full Parallax Spatial Displays,” Proc. Soc. Photo-Opt. Instrum. Eng. (SPIE), 3011:105–112 (Feb. 10–11, 1997).